Networks, such as using Dense Wave Division Multiplexing (DWDM), Optical Transport Network (OTN), Ethernet, Multiprotocol Label Switching (MPLS), and the like, are deploying control plane systems and methods. Control planes provide an automatic allocation of network resources in an end-to-end manner. Exemplary control planes may include Automatically Switched Optical Network (ASON) as defined in ITU-T G.8080/Y.1304, Architecture for the automatically switched optical network (ASON) (February 2012), the contents of which are herein incorporated by reference; Generalized Multi-Protocol Label Switching (GMPLS) Architecture as defined in IETF Request for Comments (RFC): 3945 (October 2004) and the like, the contents of which are herein incorporated by reference; Optical Signaling and Routing Protocol (OSRP) from Ciena Corporation which is an optical signaling and routing protocol similar to Private Network-to-Network Interface (PNNI) and Multi-Protocol Label Switching (MPLS); or any other type control plane for controlling network elements at multiple layers, and establishing connections among nodes. Control planes are configured to establish end-to-end signaled connections such as Subnetwork Connections (SNCs) in ASON or OSRP and Label Switched Paths (LSPs) in GMPLS and MPLS. Note, as described herein, SNCs and LSPs can generally be referred to as services, calls, connections, etc. in the control plane and are referred to herein as services. Control planes use the available paths to route the services and program the underlying hardware accordingly.
In addition to control planes, which are distributed, a centralized method of control exists with Software Defined Networking (SDN) which utilizes a centralized controller. SDN is an emerging framework which includes a centralized control plane decoupled from the data plane. SDN provides the management of network services through abstraction of lower-level functionality. This is done by decoupling the system that makes decisions about where traffic is sent (the control plane) from the underlying systems that forward traffic to the selected destination (the data plane). An Example of SDN includes OpenFlow (www.opennetworking.org/sdn-resources/onf-specifications/openflow/), the contents of all are incorporated by reference herein. Note, distributed control planes can be used in conjunction with centralized controllers in a hybrid deployment such as using the controller for overall management and the control plane for implementing connections based on controller input.
Restoration (also referred to as protection) is a key feature in networks where a backup (protection) path takes over for an active (working) path of a service when there is a failure in the active path. Restoration can include dedicated, reserved protection paths (e.g., 1+1) for working paths which provide extremely fast restoration (sub-50 ms) at the expense of inefficient bandwidth usage, i.e., the protection paths are active and unused in the network. At the other end of restoration time is mesh restoration which includes computing paths at the time of failures and can lead to several seconds for restoration. Various techniques are used in between these extremes (dedicated protection and mesh restoration with path computation upon failures) to balance the inefficient use of bandwidth versus restoration time.
In the context of network level protection, e.g., mesh restoration and variants thereof, the protection path is not necessarily known a priori; although some mesh restoration techniques provide precomputed paths. Network-level protection provides a determination of the protection path at the time of the network event contrasted with dedicated protection (e.g., 1+1) which has a dedicated path already provisioned. Thus, in network level protection, there are no assurances for a service. At best, the network operator knows there will be multiple attempts to restore the service, and there will be a notification (alarm) if the service is unable to restore. This makes proactive planning difficult. There are no available mechanisms for a network operator to provide any assurance a priori that a particular service will have a set number of available mesh protection routes available with the set number an adjustable value that can be set by the network operator.
Further, there is no current mechanisms to proactively measure the state of the network level protection over time, e.g., how many alternative protect routes exist for a given service or call at any given time. Such visibility of these proactive measurements would provide valuable insight into the state of the network and any remedial actions required therein.